1. Field of the Invention
The invention relates to a drive device suitable for use, for example, for driving a piston pump.
2. Description of the Prior Art
Piston pumps known in the industry are embodied for instance with eccentric devices or eccentric drives, by means of which rotary motions of a shaft such as this shaft of an electric motor are converted, via an eccentricity disposed on the motor shaft, into translational motions of the piston elements of the piston pumps. The translational motion of a piston element of a piston pump, given a circular eccentricity, corresponds to a sinusoidal motion whose zero crossovers each occur cyclically after an angle of motor shaft rotation of 180°. In general, one operating cycle of a piston pump includes one intake phase and an ensuing pumping phase of the piston pump, which occur cyclically in succession over an angle of motor shaft rotation of 360° and each take place within one-half of an operating cycle.
To even out pressure pulsation of a piston pump over the operating cycle of the piston pump without additional piston elements, camlike eccentricities are employed. The use of camlike eccentricities offers the capability of increasing the proportion of the pumping phase of a piston pump relative to an intake phase in one operating cycle of a piston pump. If the stroke volume of the piston pump is unchanged, this means that the same stroke volume of a piston pump is pumped, during what is now a longer pumping phase, with a lesser pressure increase toward the pumping side of the piston pump.
However, a disadvantage here is that in the region of contact between a piston element of a piston pump and a camlike eccentricity, high sliding friction forces occur, which leads to undesirably high power losses, and such piston pumps are therefore distinguished by a short service life.